Background
In August 2023, Smart Chemical Services (SCS) entered into a partnership with a Permian Basin operator in Reagan County, Texas, as an aggressive horizontal drilling program was being initiated. The wells quickly proved successful, with production rates exceeding 1000 barrels of oil per day. However, with such high production levels, downtime became a critical issue, as any interruption in operations was costly.
The operations team faced significant challenges in keeping the wells running smoothly. Through careful investigation, it was determined that the primary causes of failure were microbial induced corrosion (MIC) and the deposition of FeS (iron sulfide) on the tubing. The MIC was leading to holes in the tubing, while the FeS buildup was exacerbating the situation, contributing to under deposit corrosion, mechanical failures and further downtime. Identifying these root causes was a crucial first step in addressing the issues and optimizing the wells' performance for long-term production.
Survey
Smart Chemical Services (SCS) conducted a thorough survey to validate the findings in the field, confirming that the issues identified aligned with the results from failure analysis. The survey provided crucial insights into the underlying causes of the tubing failures, reinforcing the connection between microbial induced corrosion (MIC) and under deposit corrosion due to FeS buildup.
A Complete Water Analysis further supported the findings, revealing high concentrations of iron (Fe) in the water. This elevated iron level, combined with the high scaling tendencies identified in the outputs of ScaleSoft Pitzer, was found to contribute significantly to the corrosion and scale buildup in the wells. The presence of iron, along with the scaling tendency, amplified the challenges of microbial corrosion, leading to rapid degradation of tubing and equipment.
By validating these results through both field observations and laboratory analysis, SCS was able to pinpoint the root causes and set the stage for implementing a tailored chemical treatment program to address the corrosion, scaling, and production downtime.
Recommendation
Upon being awarded the business, Smart Chemical Services (SCS) quickly implemented an aggressive chemical program designed to address the identified issues of corrosion, FeS deposition, and scaling. A combination product was introduced to target corrosion, FeS, and CaCO3 (calcium carbonate), specifically applied to the wells experiencing the most significant problems. This treatment aimed to improve corrosion rates and eliminate solids deposition.
In addition to the combination product, a large-scale biocide program was put into action. This program focused on controlling the microbial populations contributing to microbial induced corrosion (MIC). Biocide squeeze jobs were performed and scheduled on a recurring basis, ensuring that the wells remained free from the bacteria responsible for corrosion. The key to success in this program was a combination of high-quality chemistry and expert application, ensuring that the biocides were applied effectively to control the bacteria and protect the integrity of the wells.
By taking these comprehensive actions, SCS was able to proactively address the challenges, ultimately leading to a significant reduction in corrosion and solids build up, both of which contributed to more stable and efficient production.
Monitoring
To ensure the effectiveness of the aggressive chemical treatment program, Smart Chemical Services (SCS) implemented a robust monitoring plan. This plan was designed to closely track the results and validate that the treatments were addressing the root causes of the issues. Key components of the monitoring strategy included:
- Weekly Fe/Mn (Iron/Manganese) Testing – Regular monitoring of iron and manganese levels helped assess the progress of corrosion and solids deposition, enabling quick adjustments to the chemical treatment program as necessary.
- Monthly Complete Water Analysis (CWA) – The CWA was conducted monthly to evaluate water quality, including the concentration of scale-forming elements and the overall chemical effectiveness in mitigating scaling tendencies.
- Weekly Serial Dilution Bottles – These were used to assess the effectiveness of the biocide program by tracking microbial activity and ensuring that the treatments were sufficiently controlling bacteria.
Additionally, the Red Light Green Light approach was utilized for tracking results. This system allowed the SCS team to visually identify well areas that required further treatment (red light) or areas that were responding well to the treatment and could be optimized with less frequent or lower dosages (green light). This dynamic approach enabled the team to focus additional attention on problem areas that might need extra treatment while also reducing the frequency of treatments in areas that showed improvement.
By continuously tracking and adjusting based on these results, SCS was able to maintain an agile and responsive treatment strategy, optimizing chemical use while ensuring that performance remained high and problems were addressed promptly.
Results
The ultimate measure of success for Smart Chemical Services (SCS) was extending the run times of the wells, minimizing downtime, and ensuring consistent production. By closely collaborating with engineering and operations teams, SCS was able to make significant improvements in well performance. Over a 12-month period, the results were impressive:
- Overall failure rate was reduced by 65%, significantly decreasing the frequency of well failures and the associated downtime.
- Chemically-related failure rates were decreased by 85%, demonstrating the effectiveness of the targeted chemical treatments in preventing corrosion, scale deposition, and microbial-induced issues.
This 85% reduction in chemically related failures directly reflects the success of SCS’s aggressive chemical program, biocide treatments, and consistent monitoring efforts. The ability to achieve such a dramatic turnaround in a relatively short period underscores the value of SCS’s collaborative approach, expert chemical application, and ongoing optimization of treatments. This success has not only extended the run times of the wells but also contributed to greater overall efficiency and cost savings for the operator.